Electrical submersible well pumps (ESP) are often used to pump liquids from hydrocarbon producing wells. A typical ESP includes a pump driven by an electrical motor. Production tubing, which comprises pipes having threaded ends secured together, supports the ESP in most installations. The pump normally pumps well fluid into the production tubing. A power cable extends alongside the production tubing to the motor for supplying power.
In one type of ESP, the power cable normally has on a lower end a splice that connects it to a motor lead. The motor lead extends alongside the ESP and has a motor connector or pothead on its lower end that connects to an upper end of the motor to supply power. The motor lead may have three conductors bundled together, one for each phase of power being supplied. Alternately, the motor lead may comprise three separate metal tubes, each containing one of the power conductors, and each having a connector on the lower end.
A variety of motor connectors are known. Most include a connector housing with a rigid insulator located in a cavity. The power conductor joins an electrical connector terminal. The insulation layer on the power conductor abuts the rearward end of the connector terminal. A resilient insulator within the rigid insulator seals around the insulation layer of the power conductor. The resilient insulator thus compresses the portion of the insulation layer that it seals against.
While successful, there is a fine line between too little stress on the insulation layer and not making a seal, and putting too much stress on the insulation layer, pinching it. The pinching could cause a leak and electrical failure.